It is known for automatically deboning to mount poultry breast caps on mandrels and to move these mandrels by an endless conveyor through a number of processing stations. To reduce the required floor space for this equipment the conveyor is looped about spaced sprockets with straight conveyor sections extending in a vertical plane one above the other. When processing stations are arranged along both the upper and lower conveyor sections the floor space requirement can be optimized. Automatic breast cap deboners that use this principle are known from U.S. Pat. Nos. 4,557,017, 4,873,746 and EP 0207553. In these known methods and apparatuses the mandrels are upside down when in the lower conveyor section. It has since been found that processing breast caps when suspended upside down from mandrels and prone to gravity leads to critically complex processing stations, which is reflected in their frequent necessary maintenance and adjustment. There has been some benefit in de-skinning when the breast caps are inversed. Nonetheless de-skinning is best done in a direction from the tail end to the head end of a breast cap. However in these known conveyor systems the mandrels are conveyed over the de-skinning units with the head end of the breast cap leading, which has resulted in less than optimal de-skinning results.
Accordingly it is an object of the present invention to propose an improved method and system for automatically deboning poultry breast caps containing meat and a skeletal structure to obtain breast fillets therefrom. In particular a method and system that is economic in floor space requirements, but which keeps the mandrels in an upright position, except for de-skinning. Furthermore it is an object to perform de-skinning from the tail end to the head end. In a more general sense it is thus an object of the invention to overcome or ameliorate at least one of the disadvantages of the prior art. It is also an object of the present invention to provide alternative structures which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively. Alternatively it is an object of the invention to at least provide the public with a useful alternative.
To accomplish these objects the invention provides for a method and an system as defined by the appended claims.